Makes 18 appetizers.
- 1 Tbsp. olive oil
- 1 medium red onion
- 1 Tbsp. balsamic vinegar
- 1/2 cup mayonnaise
- 1 Tbsp. basil, chopped
- 1/2 Tbsp. chives, chopped
- 1 tsp. lemon juice
- Salt and pepper, to taste
- 18 baguette slices, toasted
- 9 slices roast beef, thinly sliced and cut in half
- 9 slices (about 9 oz.) muenster cheese, cut in half
Preheat broiler to high. In a large skillet, on medium high, cook the olive oil and onions for 5 to 7 minutes or until the onions are translucent and starting to brown, stirring often. Stir the balsamic vinegar into the onion mixture and cook for another 2 minutes or until the vinegar in absorbed. Remove from heat.
In a small bowl, mix the mayonnaise, basil, chives, lemon juice, salt and pepper to make an herb mayonnaise. Spread one side of each toasted baguette with the herbed mayonnaise, top with 1/2 slice of roast beef, balsamic red onions and 1/2 slice of Muenster cheese. Place the crostini on a cookie sheet and place under the broiler until the cheese is melted and bubbling slightly. Serve immediately.
*Most of the ingredients can be made ahead and assembled at the last minute. Even the balsamic onions can be prepared ahead and microwaved to warm them up before assembling this tasty appetizer.